Commotio cordis occurs mostly in boys and young men average age 15 , usually during sports , most frequently baseball, often despite a chest protector.

It is usually caused by a projectile, but can also be caused by the blow of an elbow or other body part. Being less developed, the thorax of an adolescent is likely more prone to this injury given the circumstances.

The phenomenon was confirmed experimentally in the s, with research in anaesthetized rabbits , cats and dogs. Commotio cordis is a very rare event, but nonetheless is often considered when an athlete presents with sudden cardiac death.

Some of the sports which have a risk for this cause of trauma are baseball , American football , association football , ice hockey , polo , rugby football , cricket , softball , pelota , fencing , lacrosse , boxing , karate , kung fu , and other martial arts.

Children are especially vulnerable, possibly [ citation needed ] due to the mechanical properties of their thoracic skeleton. From to spring , the USA National Commotio Cordis Registry had cases recorded, with about half occurring during organized sports.

Commotio cordis may also occur in other situations, such as in children who are punished with blows over the precordium, cases of torture , and frontal collisions of motor vehicles the impact of the steering wheel against the thorax, although this has decreased substantially with the use of safety belts and air bags.

In one fatality, the impact to the chest was the result of an exploding whipped cream canister. In contrast, the precordial thump hard blows given over the precordium with a closed fist to revert cardiac arrest is a sanctioned procedure for emergency resuscitation by trained health professionals witnessing a monitored arrest when no equipment is at hand, endorsed by the latest guidelines of the International Liaison Committee on Resuscitation.

It has been discussed controversially, as—in particular in severe hypoxia—it may cause the opposite effect i. In a normal adult, the energy range involved in the precordial thump is five to 10 times below that associated with commotio cordis.

The small window of vulnerability explains why it is a rare event. That also explains why the heart becomes more vulnerable when it is physically strained by sports activities:.

The cellular mechanisms of commotio cordis are still poorly understood, but probably related to the activation of mechanosensitive proteins, ion channels.

These trigger extra electrical excitation waves which, if occurring right at the trailing edge of a previous electrical cycle, can give rise to ventricular fibrillation.

Impact energies of at least 50 joules are estimated to be required to cause cardiac arrest, when applied in the right time and spot of the precordium of an adult.

Also an upper limit of impact energy is applied to the heart; too much energy will create structural damage to the heart muscle, as well as causing electrical upset.

This condition is referred to as contusio cordis from Latin for bruising of the heart. On isolated guinea pig hearts, as little as 5 mJ were needed to induce release of creatine kinase , a marker for muscle cell damage.

The risk would probably be reduced by improved coaching techniques, such as teaching young batters to turn away from the ball to avoid errant pitches, according to doctors.

Defensive players in lacrosse and hockey are now taught to avoid using their chest to block the ball or puck. Starting in , high school lacrosse players are penalized, and play stopped immediately, if they enter their own goal crease with the apparent intent of blocking shots or acting as goalkeeper.

Chest protectors and vests are designed to reduce trauma from blunt bodily injury, but this does not offer protection from commotio cordis and may offer a false sense of security.

This ineffectiveness has been confirmed by animal studies. Development of adequate chest protectors may prove difficult. Most cases are fatal.

Commotio cordis is the leading cause of fatalities in youth baseball in the US, with two to three deaths per year. Get help from other users in our forums.